Computerized hazardous material response tool

ABSTRACT

A computer-based method and apparatus for identifying hazardous materials based on observable physical properties and signs and systems of exposure to the hazardous materials. The observable physical properties are obtained by preprocessing plain language data to obtain normalized descriptors and modifiers pertaining to a plurality of properties and signs and symptoms. The normalized descriptors and signs and symptoms are presented to a user in lists for comparison with a sample in the field. Once a material is identified, information can be obtained from the apparatus which is necessary for response to an incident involving the hazardous material. The preferred embodiments of the invention are particularly useful to responders to a hazardous waste incident.

This application claims the benefit of my Provisional Application Ser.No. 60/469,272 filed on May 12, 2003, which is hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to a computerized apparatus, method, andsoftware for use in identifying hazardous materials and handlinghazardous materials. The invention is particularly intended for use byresponders to incidents relating to hazardous materials.

2. Description of the Prior Art

The primary problem addressed by this invention is field response tohazardous material related incidents by emergency first responders suchas law enforcement personnel, fire fighters, hazardous materialsforensics, terrorism response teams, and the like. In order to respondit is necessary to identify the hazardous material involved and findinformation and guidance needed for a safe and effective response.

The tools that are now available derive principally from authoritativedocuments that are provided by Federal Agencies including EPA, NOAA,DOT, NIH, NIOSH. and others. The responder's “bible” is probably the DOTEmergency Response Guide (ERG2000), which provides 62 individualresponse guides (orange sheets), each of which deals with a class ofhazardous material that might be a single compound or individualmaterial or a class of materials. The response guides provide safetyrecommendations and response information to protect the responders andthe public. After securing the scene the first step in using the ERG isidentifying the hazards. The ERG recommends placards, container labels,shipping documents, material safety data sheets, and rail car or traileridentification charts and provides indexes to identify the properresponse guide based on these sources. It is necessary to know what amaterial is either by name or identifying numbers to use the ERG.

The original ERG2000 is available in document form and has been portedover to computer-based access including desktop, Pocket PC, and handheldPC platforms such as software known as Hazmatter by Pocket MobilityInc., PEAC® by Arista Tek, Inc., and CoBRA™ by Defense Group, Inc. Someversions have added additional hazardous materials not in ERG andadditional response information. Particularly, CoBRA has responsematerials relevant to terrorism related incidents. Like the originalERG, all of these units require a responder to learn the identity of ahazardous material either by name or identifying numbers or placards inorder to reference the response information. The identification mustcome from external sources.

Another important reference is the EPA and NOAA chemical database thatare available as the Response Information Data Sheets and is alsoavailable in a software version distributed as CAMEO® for desktopWindows and MAC computers having >50 Mb of disk space. This applicationis developed to supply more detailed data particular to individualhazardous materials (a single compound or product), and contains dataabout over 6,000 individual materials, representing over 80,000 synonymsand trade names. The CAMEO product is built on a general-purposedatabase manager (Filemaker™). CAMEO is designed to give firstresponders and planners information about properties of a spilledmaterial and safe response. The underlying database of CAMEO is theEPA/NOAA chemical database that is the primary source of data on thephysical and chemical database. While the CAMEO database manager allowstext searching of the database, the database is not in a form to use thedatabase for identifying an unknown material by observable properties.One reason is that the database doesn't use consistent language toconvey the same or similar meaning. For instance, one material may be“heavier than air”, while another may be “denser than air”, and stillanother may be “more dense than air”. Similarly, some materials may be“crystals”, while others are “crystalline solids” or “crystallinepowder”. Also entering a color may refer to the color of the substanceitself, its flame when burning, or the color of a decomposition product.These data are very useful for confirming a suspected identification.However, it would not be a practical way of quickly identifying anunknown material by observable properties. Notwithstanding the fact thatthe data is in the database, using CAMEO or another text based search ofthe database to identify unknown materials would be a research projectrather than a tool that would be used at an emergency incident. Also,CAMEO, or other text searching with a general-purpose data base manageris too resource intensive for typical handheld computing machines in thefield today, such as 16 MB RAM, using a 16 bit 20 MHz CPU.

Another approach involves various chemical analytical tools that mightbe useful for chemical analysis, such as ionizing spectrometers,infrared fast Fourier Transforms, mass spectrometry, and the like. Theseare useful devices but require specialized technicians that are oftennot available on first response, but are more practical at a later stageof the response.

What is needed is a computer-based apparatus for identification ofhazardous materials by responders to a hazardous waste incident based onreadily observable properties of the hazardous material.

There is a further need for a computer-based apparatus for providingresponse information needed by responders to a hazardous materialsincident, such information specific to a hazardous material that wasidentified based on its observable properties.

There is a further need for a computer-based apparatus useful inidentifying a hazardous material by signs and symptoms associated withexposure to the hazardous material.

There is a further need for a computer-based apparatus useful foridentifying a hazardous material based on observable properties andsigns and symptoms of exposure, and also providing response informationneeded by responders to a hazardous material related incident in asingle apparatus which can be provided as software operable on a varietyof general use computer platforms including limited performance palm-topdevices such as PDAs and smart cell phones and the like as well aslaptop and desktop computers.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a computer-based apparatusfor use in identifying hazardous materials based on readily observableproperties of the hazardous material suitable for use by responders to ahazardous materials incident.

It is a further object of the invention to provide a computer-basedapparatus for providing response information needed by responders to ahazardous materials incident, such information specific to a hazardousmaterial that was identified based on its observable properties.

It is a further object of the invention to provide a computer-basedapparatus useful in identifying a hazardous material by signs andsymptoms associated with exposure to the hazardous material.

It is a further object of the invention to provide a computer-basedapparatus for use in identifying a hazardous material based onobservable properties and also providing response information needed byresponders to a hazardous material related incident in a singleapparatus which can be provided in a hand-held computer platform.

It is a still further object of the invention to provide acomputer-based apparatus useful for identifying a hazardous materialbased on observable properties and signs and symptoms of exposure, andalso providing response information needed by responders to a hazardousmaterial related incident in a single apparatus which can be provided assoftware operable on a variety of general use computer platformsincluding limited performance palm-top devices, such as PDAs and smartcell phones and the like, as well as laptop and desktop computers.

It is finally a further object of the invention to provide acomputer-based apparatus for use in identifying hazardous materials byfirst responders without scientific or technical training using a palmtop or portable computer programmed for identifying the material basedon readily observable properties and common language descriptors.

A first aspect of the invention is a method for preprocessing hazardousmaterial descriptions to render them useful for subsequentidentification of hazardous materials based on hazardous materialsprocessing. There are several standard references that provide data onproperties of hazardous materials, such as the chemical database in TheEnvironmental Protection Agency's CAMEO database (formerly ResponseInformation Data Sheets). Other sources for properties are the USAMRIDfor biological warfare agents. The raw data in these references might besomewhat useful for verifying a suspected identification, but it is notin a form that is readily useful for identifying an unknown hazardousmaterial. There are over 6,000 discreet materials in the CAMEO databasealone representing over 80,000 common and trade names. The plainlanguage descriptions of the materials (such as color or texture of thematerial) are commingled with other properties using the same words. Forinstance, mention of a color might refer to the color of the materialitself, to the color of the flame when the material is burned, or to thecolor of a decomposition product. Also, synonyms are frequently foundand different phrases are used with similar meanings. For instance, onematerial may be “heavier than air”, while another may be “denser thanair”, and still another may be “more dense than air”. Similarly, somematerials may be “crystals”, while others are “crystalline solids” or“crystalline powder”. These factors would make word searches of thedatabases difficult to use for identification of an unknown hazardousmaterial even if a sophisticated database manager was available with askilled user. The data must be preprocessed into useful information, andput into a format from which a user can select the relevant propertieshe observes in the field. A method according to the invention isdescribed in the steps that follow:

-   -   1. contextually parsing plain language descriptions of the        hazardous materials to identify a list of relevant descriptors        and a plurality of modifiers pertaining to observable properties        of the hazardous materials.    -   2. classifying and organizing the descriptors and modifiers into        a plurality of property groups each of which describe a property        of a hazardous material. In the preferred embodiment of the        invention, the properties chosen are color, texture, and odor.    -   3. normalizing the list of descriptors and modifiers by        replacing synonymous words and phrases with consistent        normalized wording.    -   4. assigning unique binary values to each descriptor and each        modifier in each property group, such that one binary value        represents that the descriptor or modifier is “present” in the        description of a particular hazardous material, and the other        binary value indicates that the descriptor or modifier is absent        in the description of the material. Preferably the “present”        value is 1, and the “absent” value is 0. When this step is        completed there are a plurality of property groups (three in the        preferred example) each of which is a sequence of bits in which        each bit represents either one descriptor or one modifier or is        unassigned. A full record comprises one of each of the plurality        of descriptor groups in a predetermined order and represents a        full description of one hazardous material. Also, within each        property group the modifiers are grouped together at one end of        the bit sequence of that group.    -   5. compiling together a computer usable file comprising a        sequence of records, such that each record represents one        hazardous material. In the preferred embodiment, the number of        bits in each property group, is equal to or evenly divisible        into a natural word size of a computer on which the data will be        used. In the preferred example, color and texture have 32 bits        each and odor has 64 bits, so a fixed length record has 128        bits.

Another aspect of the invention is a computerized method for identifyinga hazardous material. The method, implemented in software operating ageneral purpose computer, is preferably intended to run well on aminimal capability handheld or palm computer, typically 16 MB, and a CPUof 20 MHz, and 16 bit CPU, having an input device, an output device, aCPU, and computer memory. It will of course also operate on more capablelaptop or desktop computers. The invention could also be implemented infirmware, in whole or in part, and could be made as a single purposecomputing device. The method is comprised of the steps that follow.

-   -   1. storing a first database in the computer memory. Each record        represents a hazardous material and comprises of a bit sequence        wherein each bit can be assigned either a “present” value or an        “absent” value wherein each bit is either a normalized        descriptor of an observable property of a hazardous material, a        special modifier, or an unassigned position. Preferably the        “present” value is 1, and the “absent” value is 0. In a        preferred embodiment the first database is a sequential list of        fixed length records, such as previously described in the first        aspect of the invention wherein record has a relative position        in the sequential list.    -   2. storing a computer representation in the computer memory, of        response information relevant to use with the hazardous        materials represented in the first sequential list. These        include such information as EPA Response Information Data Sheets        (RIDS), the Department of Transportation Emergency Response        Guides (ERG2000), and the NIOSH Pocket Guides. These response        information are compressed and stored for access according to        the sequential position of the hazardous material to which they        pertain or random access. The storage is preferably such as to        allow display of the data in a format and organization on screen        that is similar to the original source.    -   3. displaying property lists on the computer output device,        preferably the screen, of the type from which a user can make        selections, wherein each property list pertains to one of the        observable properties of hazardous materials in the sequential        list. The choices are either normalized descriptors of the        observable property or special modifiers pertaining to the        observable property. The preferred format for display is pop up        menus.    -   4. accepting one or more selections from a user from one or more        of the property lists and storing the user defined selections in        computer memory in a format compatible with comparison with a        record in the sequential list. As described in the first aspect        of the invention, in the preferred embodiment, the fixed length        records each consist of an ordered sequence of property groups,        each property group is an ordered sequence of bits, each bit        represents the presence or absence of a descriptor or modifier        or is unassigned, and within a property group the modifiers are        grouped together, and the presence of modifiers is optional. The        property groups in the fixed length records correspond to the        property lists displayed, and the descriptors and modifiers on        the property list correspond to descriptor and modifier bits in        property groups. The user-defined selections from each property        list are preferably stored in a bit sequence with the same        sequence as the corresponding property group in the fixed length        records. If a particular property group includes modifiers as        well as descriptors, a user defined selection will consist of a        user defined descriptor bit map and a user-defined modifier        bitmap.    -   5. comparing the user selection with a fixed length record        representing a hazardous material. This step comprises making at        least one bit wise logical comparison between a user defined        selection and fixed length record. Many possible criteria for a        match will be apparent, however it has been found that one        preferred method is of particular value. Based on trials, the        preferred criteria is to consider a material a potential match        to a user selection if for each descriptor group in the fixed        length record that corresponds to a property list from which at        least one selection was made, there is at least one bit with        “present” value that corresponds to a selected bit, if any, in        the user defined descriptor bitmap, and that there is at least        one bit with the “present” value that corresponds to a selected        bit, if any, in the user defined modifier bitmap. This step can        be implemented by making two bitwise AND operations for each        property list from which one or more selections were made. For        either a 16 bit or 32 bit CPU and a 32 bit descriptor list this        is a very search efficient operation, which is important for low        performance hand held computers. This step is repeated for each        hazardous material record in the sequential list and a list of        possibly matching materials is reported to the user on the        display device.    -   6. allowing a user to highlight a possible hazardous material        and select relevant information on response to an incident        involving the highlighted hazardous materials. The data are        extracted from the computer representation of relevant response        information and are displayed in a manner similar to the        original government documents from which the data was extracted.        Having both comprehensive identification and response        information for hazardous materials on a single palm held        computational device is believed to be unique to this        application.

An optional and very useful feature of the method is identification of ahazardous material by signs and symptoms of exposure to the hazardousmaterial. In the case of signs and symptoms the acts of parsing,classifying, normalizing, assigning and compiling are carried out verymuch as in the first aspect of the invention for observable properties.However, it has been found that the frequency of occurrence of differentsigns and symptoms is very skewed, skewed such that about 20% of thesigns and symptoms are responsible for 80% of the occurrences. Theperformance on a relatively low performance computer can therefore bedramatically improved by listing the bits in a record by order ofoccurrence. There are no modifiers for signs and symptoms. A preferredmethod is compiling a list of sequential records for signs and symptomswith the bits in each record arranged by descending order of frequencyof occurrence, and to report the materials with the highest rank, whererank is the number of matching bits between the user selection and asign/symptom record. The evaluation is carried out by examining therecords one word (32 bits) at a time such that in most cases it will notbe necessary to go beyond the first word of each record. In thepreferred embodiment there are 128 bits per record. The sign/symptomsequential list, the sequential list of records representing physicalproperties, and the computer representation of response information arepreferably all in memory concurrently.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with regard to the followingdescription, appended claims and accompanying drawings, where:

FIG. 1 is a flow chart of the method of making a database for use in acomputerized tool for identifying hazardous materials according to apreferred embodiment of the invention.

FIG. 2 is a table of preferred values of normalized descriptors andspecial modifiers in the database of FIG. 1.

FIG. 3 is a table of preferred values of classified signs and symptoms.

FIG. 4A is a drawing of a computer suitable for practicing theinvention.

FIG. 4B is a schematic of the computer.

FIG. 4C is a memory card with software instructions and data files forcarrying out the invention.

FIG. 5A is a screen shot of the search mode of a preferred embodiment ofthe invention on startup.

FIG. 5B is a screen shot of the materials identification page.

FIG. 5C is a screen shot of a signs and symptoms identification page.

FIG. 5D is a screen shot of an Emergency Response Guide Orange Sheet.

FIG. 5E is a screen shot showing recommended protection equipment.

FIG. 6 is a flow sheet for processing data to identify potentialhazardous materials.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention involves a computerized tool for use in connection withhazardous materials related incidents. While it will be apparent tothose skilled in the art that the invention has a variety of uses, anintended use is for responders to a hazardous materials incident, suchas police, fire, emergency medical personnel, hazmat teams, and thelike.

One aspect of the invention is a hazardous material property database,and a method of making the database for maximum utility for fieldidentification of hazardous materials by responders to hazardous wasteincidents, preferably first responders. Another aspect of the inventionis a computer including data and software instructions in computermemory that allows a user to identify a hazardous material based onobservable physical properties, by choosing descriptors and modifiers ofa physical property from prepared lists of normalized descriptors andmodifiers. Preferably, the user may obtain response information bymarking a hazardous material and selecting the desired type of data.Another aspect of the invention is a method of identifying hazardousmaterials in the form of computer instructions and data files incomputer useable form which when loaded and executed will operate on ageneral purpose computer. A preferred platform is a hand held or palmtop PDA device having less than 16 MB of memory and about 9.8 MB of freememory, and the invention should be capable of operation on such amachine. Such a palm held machine 30 is shown in FIG. 4A. FIG. 4B showsthe memory 32 and processor 34 in the machine. In the memory is shownthe observable properties database 37, and the signs and symptomsdatabase 38, both of which are composed of sequential records in thepreferred embodiment. Also shown are the response information database39 and the computer program logic 40 in memory. FIG. 4C shows a memorycard 36 with computer programming instructions and data in a computeruseable form for carrying out the invention. It will be understood tothose skilled in the art that computer useable form can also include anyformat appropriate for the computer, including but not limited to allmanner of disks and including transferring files and data over anetwork, by direct connection, or by IR or radio signals.

Important features of a preferred embodiment of the inventionimplemented on a portable handheld PDA include:

-   -   1. ability to identify a hazardous material based on making        selections from pre-prepared lists of including both normalized        descriptors and modifiers relevant to observable properties. The        normalized descriptors and modifiers are derived by contextually        parsing plain language descriptors and profiles of hazardous        materials to identify relevant descriptors and modifiers and        normalizing these to a common lexicon.    -   2. ability to identify a hazardous material based on making        selections from pre-prepared lists of normalized signs and        symptoms of exposure to hazardous materials.    -   3. ability to reference response information needed by a        responder to a hazardous materials incident relevant to an        identified hazardous material.    -   4. data structures and computer logic for storing databases,        facilitating user inputs, and efficiently identifying hazardous        materials from the user inputs.

The invention will now be described in terms of several databases thatmay be included in the invention and how to make them, and the computerlogic and resources to carry out the invention.

Databases

Database of Observable Properties and Method of Making the Database

One component of the invention is a database of observable properties ofhazardous materials organized into a sequential list of fixed lengthrecords for use in a computerized tool for identifying hazardousmaterials. The database format is specially chosen for use in the fieldidentification of hazardous materials in the following ways:

-   -   1. The plain language profiles and descriptions of thousands of        hazardous materials found in government references are        pre-processed into property groups of normalized descriptors and        special modifiers to facilitate their use in identification of        hazardous materials. As used in this patent application a        “normalized descriptor” is defined as an attribute of an        observable property of a hazardous material, that has been        obtained by the steps of contextually parsing a multiplicity of        hazardous material profiles to identify attributes, grouping the        attributes into property groups, identifying synonymous and        similar words and phrases and replacing them with a single        standardized term which is used consistently throughout the        database. Similarly, “special modifiers” is defined as a word        which can under some circumstances describe an attribute of an        observable property of a hazardous material and under other        circumstances describe a hazardous material. For instance for        the observable property color, normalized descriptors might be        red, orange, yellow, green, blue, and colorless, while special        modifiers might be dark, light, pale, and bright. The data are        stored in a compact data structure to where the presence or        absence of each descriptor or special modifier in the        description of a hazardous material is represented by the value        of a single bit (this is equivalent to each descriptor or        modifier being assigned a distinct value that is a power of        two).    -   2. The data are grouped into property groups which have a number        of bits which is preferably a natural word size of the system        (32 bits) so that a selection made by a user can be evaluated        against 32 properties with a single bitwise logical comparison.        This improves performance substantially on low performance        machines.    -   3. All of the above factors, convert data into information to be        efficiently searched without use of a general purpose database        manager, the use of which would prohibit use on low performance        hand held devices.

Each fixed length record represents the properties of one hazardousmaterial and has a relative position in the sequential list. Each fixedlength record consists of a bit sequence where each bit eitherrepresents a normalized descriptor of an observable property, a specialmodifier, or an unassigned space. Each normalized descriptor and eachspecial modifier is represented in the bit sequence as one bit that canhave either a “present” value or an “absent” value, preferably the“present” value is 1 and the “absent” value is 0. Each record has thesame order as to which position represents a particular normalizeddescriptor, special modifier, or unassigned space. Each record ispreferably divided into a plurality of property groups. Each propertygroup is comprised of normalized descriptors relating to the propertygroups and optionally special modifiers. In the preferred embodiment,the property groups are color, texture, and odor. Examples of normalizeddescriptors of color are red, orange, yellow, green, blue, andcolorless; examples of special modifiers are dark, light, pale andbright. Note that special modifiers preferably make sense as either amodifier of a normalized descriptor or as a stand-alone word. Forinstance, it makes sense to have a dark blue material or just a darkmaterial. A preferred list of normalized descriptors and specialmodifiers is given in FIG. 2. The data base is manufactured onto acomputer useable form such as but not limited to a memory card such asthe card 36 in FIG. 4C, for use in a palm top computer, or a file forupload to a computer, or other manufactures that will be well known tothose skilled in the art.

The method of making the database for use in identification of hazardousmaterials is now discussed. The descriptions and profiles of hazardousmaterials are not organized for use in rapid field identifications. Theyare rather intended for use in finding properties of a known materialnot for identifying an unknown material. FIG. 1 is a flow chart of apreferred embodiment of a process for compiling a database for use inthe invention. The steps are as follows:

-   -   1. Using a comprehensive group of hazardous materials from        references such as the EPA/NOAA CAMEO database of over 6,000        hazardous materials, contextually parse the plain language        descriptions of the multiplicity of hazardous materials to        identify a plurality of relevant descriptors and a plurality of        modifiers pertaining to observable properties of the of        hazardous materials (10 and 11). Those skilled in the art will        appreciate that other sources may be available or become        available to supplement or replace the suggested references.    -   2. Normalize the plurality of descriptors and plurality of        modifiers into a common lexicon of normalized descriptors and        special modifiers by replacing synonyms and similar phrases with        normalized wording (12).    -   3. Classify each normalized descriptor and each special modifier        into one of a plurality of descriptor groups, wherein at least        one of the descriptor groups preferably comprises a plurality of        special modifiers. Each descriptor group represents an        observable property. In a preferred embodiment, the descriptor        groups are color, texture, and odor. The normalized descriptors        and special modifiers in the preferred embodiment are listed in        FIG. 2 (14).    -   4. Assign a binary power of 2 to each normalized descriptor and        to each special modifier in each descriptor group, such that        each normalized descriptor and each special modifier in each        descriptor group is represented by exactly one bit and such that        the modifiers are grouped together within each descriptor group.        Since there will be more descriptors than modifiers it is        convenient to assign the modifiers the lowest values in each        descriptor groups, so that each descriptor group that contains        one or more modifiers is a bitmap consisting of a descriptor        portion and a modifier portion. In using the database to        identify a hazardous material by comparing a user made selection        with a record in the database, bits representing normalized        descriptors and special modifiers will be treated separately        (16)    -   5. Assign an order to each of the plurality of descriptor        groups, such that each fixed length record consists of a        sequence of descriptor groups in the order. For instance, in the        preferred embodiment the order is color, texture, and odor (18).    -   6. Assign appropriate values to each descriptor group in each        fixed length record that represents a hazardous material, such        that the sequence of descriptor groups describes the hazardous        material. This is accomplished by assigning each descriptor bit        and each modifier bit as being present or absent in each        descriptor group of a record according to whether it is present        or absent in the description of the hazardous material that the        record represents (20).    -   7. Compile the database into a sequential list of fixed length        records in computer useable form (22).        Optional Signs and Symptoms Database

An optional feature in identification of hazardous materials is theability to identify a hazardous material by signs and symptoms ofexposure to the hazardous material. This may be very useful to a firstresponder who arrives at the scene of an incident and finds victims indistress from exposure to a hazardous material. As with the database ofobservable properties, the signs and symptoms data are preferablyorganized as a sequential list of fixed length records with each bit inthe record representing the presence or absence of one normalized signor a symptom of exposure, or an unassigned space.

The signs and symptoms database is compiled in a manner similar to theproperties database. The database is compiled by the following acts:

-   -   1. Gather signs and symptoms for exposure to those hazardous        materials for which it is available. Sources include the EPA        Response Information Data Sheets, National Institutes of Health        National Toxicity Program Database, and the ATSDR database,        preferably in their latest editions or revisions. Those skilled        in the art will appreciate that over time new sources may become        available to supplement or replace the listed items. The        signs/symptoms database has fewer materials listed than the        observable properties database; not every hazardous material in        the properties database has available signs and symptoms of        exposure.    -   2. Normalize signs and symptoms into a common format by        eliminating synonyms and preferably using common language rather        than medical terminology. For instance, tearing can be used to        replace lacrimation, watery eyes, causes tears, watering eyes,        tearing eyes, etc.    -   3. Classify the normalized signs and symptoms into categories.        There are eight categories in the preferred embodiment,        including appearance, respiratory, behavior, cardiovascular,        skin, digestive system, eyes, and temperature. There are 128        signs and symptoms in the preferred embodiment. A table of the        classified signs and symptoms is given in FIG. 3    -   4. Assign a binary power of two to each sign and symptom, so        that each bit in the record represents the presence or absence        of one sign or symptom. Unlike the properties database, signs        and symptoms are preferably listed in order of frequency of        occurrence rather than by category group. This is because of the        fact that the signs/symptoms data are very skewed, with about        20% of the signs or symptoms accounting for 80% of the        occurrences. If it is desired to quickly search the data for the        most likely hazardous materials corresponding to observed        symptoms, a much more efficient search will be facilitated if        the signs and symptoms are arranged in order of frequency of        occurrence.    -   5. Assign an appropriate value to each bit in each record        corresponding to a hazardous material depending on whether the        assigned sign or symptom is present or absent.    -   6. Compile the database into a sequential list of fixed length        records in computer useable form.        Response Information Database

Once a hazardous material has been identified, it is preferable to beable to display response information that a responder will need tohandle an incident involving the hazardous material. The informationincludes:

-   -   1. Name, synonyms, United Nations Number (UNNA), Chemical        Abstract Service Number (CAS)    -   2. Emergency Response Guidebook (ERG2000)—This is a guidebook        that was prepared by the US Department of Transportation,        Transport Canada, and the Secretariat of Communication and        Transportation of Mexico. The guidebook contains 62 individual        guides (orange sheets) with safety and emergency response        information for a class of hazardous materials and indexes for        choosing the appropriate index for a particular hazardous        material based on name or identification number.    -   3. EPA/NOAA Response Information Data Sheets (now found in        CAMEO).    -   4. Hazards Overview—Including airborne concentration immediately        dangerous to life and health (IDLH) from NIOSH, EPA and NIH        sources, temporary emergency exposure levels (TEEL), shipping        hazard, water hazard, other hazards.    -   5. Chemical Profile—Text    -   6. Reactive Groups—Text    -   7. Physical Properties such as auto ignition, boiling point,        ERPG1, ERPG2, ERPG3 (ERPGx values are maximum allowable air        concentration for x hour exposure without harm), flash point,        lower explosive limit, upper explosive limit, melting point,        specific gravity, temporary emergency exposure limits (1, 2, and        3 hours), vapor pressure, vapor density, ionization potential,        and correction factors    -   8. Emergency Medical Service—signs and symptoms, first aid,    -   9. Protective Clothing—permeation threshold times for various        materials and types of clothing    -   10. National Fire Protection Association (NFPA) placard.

The response information is reduced to compressed form such that can beaccessed for any chosen hazardous material discovered in a propertysearch, signs and symptoms search (if applicable) or search by name,synonym, UNNA or CAS Number. The compression of data is important to theoperation on portable computers, such as hand held or palm topcomputers, since some of the references are large text documents.

The original reference for each material is the relative position of thecorresponding record in the Observable Properties Database. This linksto a master record for every material in the system. The master recordallows the program to quickly present an overview of any material foundin the system. Also, the data found in a master record can be used askeys into the rest of the data, allowing retrieval of more detailed datawhenever the user requests an appropriate detailed data page.

One particularly large document that is preferably available in memoryis the Emergency Response Guidebook (ERG2000). The data records for theERG source alone are 1.58 MB as supplied without display or formattinginstructions. An Acrobat version of ERG2000 is 1.75 MB and 383 pages.The preferred method of storing the ERG is a Hoffman coding technique ofstoring an alphabetically sorted list of each unique sentence in thedocument (there is substantial reuse of sentences), along with indexesand other data needed to re-create the source data in about 234 KB. Themethods of indexing and linking to particular materials are conventionaland well known to computer programmers.

Another area of the data requiring special treatment is providingguidance on chemical protective clothing (whether and how long aparticular material of construction can be counted on to provideprotection for a particular hazardous material). Chemical protectiveclothing source data comes primarily from the NIOSH Pocket Guide, theEPA's RIDS database, and 3M Corporation's Guide to Permeation, whichprovides extensive data regarding their line of chemical protectiveclothing materials, which constitutes approximately 70% of all chemicalprotective clothing/materials. Data sources are provided with differentprecision in different sources. As this system is intended primarily asa field guide for first responders, the data are normalized into broadcategories that will be useful for the intended purpose and also reducethe amount of data required to load into memory. For instance, a firemandoesn't need permeation times broken down by the minute even though thatinformation may be available. The permeation breakthrough data is storedand available for presentation based on twelve categories (stored as 12bits) based on the following categories: No data, <1 hour, 1-3 hours, atleast 3 hours, <1 hour (limited data), 1-3 hours (limited data), atleast 3 hours (limited data), at least 4 hours, at least 5 hours, atleast 6 hours, at least 8 hours, and at least 12 hours. A given chemicalmay have numerous types of chemical protective clothing, in thecategories of garments, gloves, boots, similar fabrics and face-shields.The sequence number in the Observable Property Database correlates eachto a material. By this manner of data compression the permeationbreakthrough data is reduced from 1 MB to about 68 KB.

Text data such as first aid information, signs and symptoms information,are available in the literature as free text data from multiple sources.The text as supplied is preferably pre-processed and normalized into aset of single line sentences that express all the instructions in theoriginal sources. The normalized sentences are stored in memory alongwith indexes to create the original instructions for each hazardousmaterial. Physical properties are preferably sorted to identify all theunique values of a given property, and then store indexes to lookup theproper data.

The NFPA hazard code is compressed into one 16 bit word for eachmaterial.

Computer Logic

A preferred language for implementation is Java using the Superwabaplatform that is an open source platform for PDA applicationsdevelopment available on the Internet at “www.superwaba.com.br”. Thisplatform has a Virtual Machine implemented for windows, Palm OS, PocketPC (Windows CE), and Symbian devices.

The computer logic follows the event driven model, where the events areinitiated by user inputs. In a preferred embodiment implemented on ahandheld PDA user inputs are generally made by a stylus and touchsensitive screen, and output is shown on the screen. This is probablythe most convenient platform for an emergency responder and it is animportant consideration that the invention be capable of operation onsuch familiar handheld units as a Palm OS 3.0 or higher, MicrosoftPocket PC 2002, 2000, HPC211 or PPC211 device based on ARM, MIPS, or SH3processor with 9.8 MB main memory free. Of course, it will also operateon Windows NT, ME, 2000, XP, or 98 with at least 9.8 MB free disk space,or Linux, Unix or Macintosh computers with an installed Java RuntimeEnvironment (JRE) 1.3 or higher.

FIG. 5A shows an opening screen 50, for the invention. Note three tabslabeled Search 52, Discovery 54, S&S 55 (Signs and Symptoms) andGlossary 56, with the Search tab 52 chosen as the opening screen. Fromthis screen one can search for a hazardous material by entering its nameor part of its name into input box 58 and pressing GO 60. An ERG GuideNumber, a Guide section, a United Nations number (UNNA) or a ChemicalAbstract Service (CAS) number may be inputted in place of the name. Theresult is reported to results box 59. In search mode a user may selectavailable data for a material by tapping the choose view menu 61. Thisbrings up a pop-up menu of response information'that is available forthis material, such as the relevant Emergency Response Guide page,isolation distance, hazards review, reactive groups, material profile,protective clothing, EMS signs and symptoms, and first aid. Tapping theappropriate item causes the computer logic to retrieve the appropriateinformation from the Response Information Database and assemble it onthe output screen. FIG. 5D shows a screen shot of an ERG page and FIG.5E shows a page with recommendations of chemical protective clothing.

A user may shift to discovery mode from this screen by tapping Discoverytab 54 in FIG. 5A. In discovery mode a user is able to identify ahazardous material by observable properties, a capability that is a keyinnovation unique to this invention. FIG. 5B shows the discovery modeinput page, with pop up menus for a user to input properties of color62, texture 64, and odor 66. By tapping any one of these menus a list ofdescriptors and modifiers pops up for selection. The descriptors andmodifiers for each property in a preferred embodiment are shown in FIG.2. These same descriptors and modifiers correspond one to one with thedescriptor groups in the database of observable properties. A user canmake as many choices from each list as she desires. When satisfied withher choices the user should tap the search icon 68. This causes thecomputer logic to form a user-defined bitmap for each list from which atleast one selection was made and store the user-defined list in memory.The user-defined bitmap for a list preferably has the same structure asthe corresponding descriptor group in the database of observableproperties and places the “present” value in the position of each userselection and the “absent” value in all of the other bit positions.Recall that some descriptor groups in the database include bothdescriptors and modifiers, and if so, the modifiers are grouped togetherso that these descriptor groups consist of a descriptor portion and amodifier portion. The same convention is preferably followed in theuser-defined bitmap. The computer logic then compares each user-definedbitmap with each record in the database of observable properties to seeif it matches according to a matching criterion.

Those skilled in the art will appreciate that there are many ways tojudge whether a user selection is a “good enough” match to a record inthe database of observable properties to report a hazardous material asa potential match for an observed material. The observable propertydatabase is set up with each bit in a descriptor group, which isassigned, representing either a normalized descriptor or a specialmodifier, and the user-defined selection from a property list whichcorresponds to the descriptor group has the same bitwise structure asthe descriptor group. Therefore, a preferred method of comparing auser-defined selection and a descriptor group is the bitwise logicalAND. For a first bit stream and a second bit stream, each bit streamhaving the same number of bits, and each bit having a position, thebitwise logical AND of the two bit streams returns a 1 for each bitposition where a 1 in the first bit stream is matched by a 1 in thesecond bit stream and returns zero otherwise. For example, 0111 AND 0001equals 0001.

While many criteria are possible, the preferred criterion is aninclusive method that will return excess potential matches at theexpense of not excluding the correct choice. This method was found to bemost useful in testing by first responders. Preferred methods thereforeshould not require that all properties of a material in the database bematched by user observation.

The preferred method considers a sample material to be a potential matchof hazardous material represented by a record in the database if foreach descriptor group in the record that corresponds to a property listfrom which at least one selection was made, there is at least one bithaving the “present” value that corresponds to a selected bit, if any,in the descriptor portion of user-defined bitmap, and that there is atleast one bit having the “present” value that corresponds to a selectedbit, if any, in the modifier portion of the user-defined modifierbitmap. In the preferred embodiment where the “present” value is 1 andthe “absent” value is 0, for each descriptor group in the record thatcorresponds to a property list from which at least one selection wasmade and therefore having a user-defined bitmap, the logical bitwise ANDis non-zero

-   -   1. between the descriptor portion of the user-defined bitmap and        the descriptor portion of the corresponding descriptor group in        the record, if a descriptor was selected from the property list,        and    -   2. between the modifier portion of the user-defined bitmap and        the modifier portion of the corresponding descriptor group, if a        special modifier was selected from the property list.        This process is repeated for each hazardous material in the        observable properties database and the potentially matching        hazardous materials are reported to the user on the output        screen. FIG. 6 is a flow diagram of the method of comparison.

One interesting property of the preferred matching criterion is that ifonly a modifier and no descriptors are chosen from a property list, themodifier will in effect serve as a descriptor. For instance, in thecolor property list if only “dark” is chosen, any dark material will bea match (recall that a “dark” material will have the “present” value inthe “dark” bit position). Also, if both descriptors and modifiers areselected, there must be at least one match between in both thedescriptor and modifier portions.

Once a list of potentially matching hazardous materials is presented toa user, the user can enter the select choose view icon 61 which makesavailable a pop-up menu of information available on a hazardous materialselected from the list. The information includes information to furtherassist in narrowing the identity of a hazardous material sample, as wellas response information. The information includes items such as therelevant Emergency Response Guide page, isolation distance, hazardsreview, reactive groups, material profile, protective clothing, EMSsigns and symptoms, and first aid. Tapping the appropriate item causesthe computer logic to retrieve the appropriate information from theResponse Information Database and assemble it on the output screen. Forexample, FIG. 5D shows a screen shot of an ERG page and FIG. 5E shows apage with recommendations of chemical protective clothing.

Another very useful feature is to search for a hazardous material bysigns and symptoms of exposure to the material. The event by which auser activates a search by signs and symptoms on a palm top embodimentof the invention is tapping the S&S tab (55) on the opening screenillustrated in FIG. 5A. This brings up a screen 70 illustrated in FIG.5C which lists eight categories of signs and symptoms 72 (five visiblein the figure, the remaining three would be viewed by scrolling down thelist) next to pop up menus 74 for entering individual indicators (signsor symptoms) in each category. The categories and indicators are listedin FIG. 3. As many signs and symptoms could be selected as desired fromeach category. When the selection process is complete, the search eventis initiated by a user tapping the search button 76. This begins thecomputer logic to begin the search.

As was previously described in the section entitled “Optional Signs andSymptoms Database” a slightly different data structure is preferred forsigns and symptoms. Like the observable properties database, thepreferred structure is a sequence of fixed length records, one recordfor each hazardous material, where each bit represents the presence orabsence of one indicator or an unassigned space. In the preferredembodiment each record is 128 bits long, and a present indicator isrepresented by the bit 1 and an absent indicator is represented by thebit 0. Unlike the observable properties database, in the signs andsymptoms data base the bits (representing indicators) are preferably notarranged within a record in groups corresponding to the categoriespresented to a user to make selections, but are rather arranged byfrequency of occurrence. As a consequence the correspondence between bitposition and indicator must be stored in a look up table. Using recordsarranged by frequency of occurrence allows a search strategy thatexploits the observation that the occurrence of the indicators is quiteskewed, with about 80% of the occurrences resulting from only 20% of theindicators.

In the case of signs and symptoms it is therefore preferred to presentthe hazardous materials in rank order, the rank of a material preferablybeing equal to the number of user inputted indicators which are presentin the material. The top ranking 25 materials are reported in thepreferred embodiment. Ranking the materials replaces the comparisoncriteria used in identifying by observable properties. The computerlogic preferably comprises the following steps:

-   -   1. Assembling a user defined indicator bitmap in the same format        as the record bitmap stored in the signs and symptoms database.    -   2. Examining each record, in turn, in the database by examining        the first word in the record by computing a bitwise logical AND        between the first word of the record and the first word of the        user defined indicator bitmap and computing a rank for each        material that equals the number of 1's in the logical AND. A        word is preferably 32 bits.    -   3. Arranging the materials in rank order.    -   4. Computing whether it is possible to exceed the rank of the        currently identified 25th ranked material by assuming that all        the bits in the remaining words of the user defined indicator        bitmap which were not matched in the first word would be matched        in the remaining words of the record, and determining whether        with this assumption the rank of the currently 25^(th) ranked        material would be exceeded.    -   5. If not possible stop and report the top 25 materials,        otherwise repeat steps 2, 3, 4 for the second word of each        record and if necessary beyond to the third and forth word.

It has been found that in most cases it is not necessary to go beyondthe first word, and that in most cases the performance is greatlyspeeded up, particularly on low speed palmtops and cell phones. When theprocess is complete, the results are reported in the results box 77.Note that to the left of each material is are a group of boxes 78 whichgive an indication of relative rank based on the number of boxes.

It will be appreciated that the preferred embodiments described providea computer based apparatus for identifying hazardous materials based ontheir observable properties and signs and symptoms of exposure to them.Once a material is identified, the information needed for response to anincident involving the material can be obtained. The preferredembodiments can be operated on palm and handheld PDA's and similardevices as well as desktop computers. The preferred embodiments dependon converting data available in authoritative sources into usefulinformation presented to a user in a form where he can make selectionsleading to a successful identification.

Although the present invention has been described in considerable detailwith reference to certain preferred versions thereof, other versions arepossible. Therefore the spirit and scope of the appended claims shouldnot be limited to the preferred versions herein.

1. An apparatus for use in hazardous materials identification,comprising: a. a computer comprising an arithmetic processor unit, anoutput device, an input device and a computer memory; b. a firstdatabase comprising a multiplicity of records in the computer memory,wherein each of the multiplicity of records represents information aboutobservable properties of one hazardous material, in the form of a bitsequence wherein each bit in the bit sequence can be assigned either a“present” value or an “absent” value and wherein each bit in the bitsequence represents a member of the group consisting of normalizeddescriptors of an observable property of a hazardous material, specialmodifiers, and unassigned positions; c. a computer representation in thecomputer memory, of response information relevant to use with thehazardous materials represented in the first sequential list; d.computer logic and resources adapted to i) display a plurality ofproperty lists on the output device of the type from which a user canmake selections, wherein each property list pertains to an observableproperty, and lists choices which are either normalized descriptors ofthe observable property or special modifiers pertaining to theobservable property; ii) accept at least one selection from the userfrom the input device from at least one of the plurality of propertylists said at least one selection being either a normalized descriptoror a special modifier and wherein the at least one selection maycomprise a plurality of different selections; iii) store in the computermemory a user defined selection from each property list from which atleast one selection was made in the form of a user defined descriptorbitmap; iv) evaluate a record in the first database to determine whethera hazardous material represented by the record is a possible matchinghazardous material based on at least one bitwise comparison of each userdefined selection with the record; and v) report the hazardous materialon the output device if it is a possible matching hazardous material. 2.The apparatus of claim 1, wherein each of the multiplicity of records inthe first database is a fixed length record, and each of the fixedlength records has a sequential position in the computer memory so as toform a first sequential list wherein each of the fixed length recordshas a relative position within the first sequential list.
 3. Theapparatus of claim 2, wherein the computer logic and resources furthercomprise logic and resources to: a. find response information for thepossible matching hazardous material using the relative position of therecord, if requested by the user; and b. report the response informationfor the possible hazardous material on the output device, if requestedby the user.
 4. The apparatus of claim 3, wherein each of themultiplicity of records in the first database comprises a plurality ofdescriptor groups each descriptor group being made up of a bit sequence,and wherein each property list corresponds to a descriptor group andeach choice on a property list corresponds to one bit in a descriptorgroup.
 5. The apparatus of claim 4, wherein the first database iscompiled by the acts of: a. contextually parsing plain languagedescriptions of a multiplicity of hazardous materials to identify aplurality of relevant descriptors and a plurality of modifierspertaining to observable properties of the multiplicity of hazardousmaterials; b. normalizing the plurality of descriptors and plurality ofspecial modifiers into a common lexicon of normalized descriptors andspecial modifiers; c. classifying each normalized descriptor and eachspecial modifier into one of a plurality of descriptor groups, whereinat least one of the descriptor groups comprises a plurality of specialmodifiers; d. assigning a binary power of 2 to each normalizeddescriptor and to each special modifier in each descriptor group,whereby each normalized descriptor and each special modifier in eachdescriptor group is represented by exactly one bit; e. assigning anorder to each of the plurality of descriptor groups, such that eachfixed length record consists of a sequence of descriptor groups in theorder; and f. assigning values to each descriptor group in each fixedlength record that represents a hazardous material, such that thesequence of descriptor groups describes the hazardous material.
 6. Theapparatus of claim 5, wherein the plurality of property lists comprisethree property lists and wherein the observable properties correspondingto the three property lists comprise color, texture, and odor.
 7. Theapparatus of claim 6, wherein the computer is a hand held computerhaving less than 16 MB of memory and wherein greater than 6000 hazardousmaterials and their response information can be identified anddisplayed.
 8. The apparatus of claim 6, wherein the computer logic andresources to display a plurality of property lists comprises logic andresources to display each of the plurality of property lists in the formof pop-up menus.
 9. The apparatus of claim 4, wherein the logic andresources to store in the computer memory a user defined selection fromeach property list from which at least one selection was made in theform of a user defined bitmap, is adapted to store the user definedselection in the form of a user defined bitmap comprising a user defineddescriptor bitmap of normalized descriptors selected if any, and a userdefined modifier bitmap which comprises a bitmap of special modifiersselected if any.
 10. The apparatus of claim 9, wherein the logic andresources are adapted such that a fixed length record represents apossible matching hazardous material, if for each descriptor group inthe fixed length record that corresponds to a property list from whichat least one selection was made, there is at least one bit having the“present” value that corresponds to a selected bit, if any, in the userdefined descriptor bitmap, and that there is at least one bit having the“present” value that corresponds to a selected bit, if any, in the userdefined modifier bitmap.
 11. The apparatus of claim 9, wherein the logicand resources are adapted such that a fixed length record represents apossible matching hazardous material, if for each descriptor group inthe fixed length record that corresponds to a property list from whichat least one selection was made, each selected bit in the user defineddescriptor bitmap, if any, corresponds to a “present” value bit in thedescriptor group, and each selected modifier in the user definedmodifier bitmap if any, corresponds to a “present” value bit in thedescriptor group.
 12. The apparatus of claim 10, wherein the logic andresources to find a matching hazardous material further comprises logicand resources to evaluate each record in the first sequential list untilevery record has been examined.
 13. The apparatus of claim 11, whereinthe logic and resources further comprises logic and resources toevaluate each record in the first sequential list until every record hasbeen examined.
 14. The apparatus of claim 2, further comprising: a. asecond database comprising a second sequential list of fixed lengthrecords in the computer memory, wherein each fixed length recordcorresponds to a hazardous material and has a relative position in thesecond sequential list and wherein each fixed length record is a bitsequence in which each bit in the bit sequence represents an indicatorof an exposure to a hazardous material and wherein every bit is either a“present” value or an “absent” value, and wherein every indicator iseither a sign or a symptom; b. computer logic and resources adapted toi) display indicators on the output device in the form of at least onelist from which a user can make selections, wherein each indicatorcorresponds to a bit in the bit sequence; ii) accept at least oneindicator selection from the user from the input device of a indicatorwherein the at least one indicator selection may comprise a plurality ofdifferent selections; iii) store in the computer memory a user definedindicator bitmap corresponding to the at least one indicator selection;and iv) evaluate a record in the second sequential list of fixed lengthrecords by calculating a rank based on a bit wise comparison between theuser defined indicator bitmap and the bit sequence.
 15. The apparatus ofclaim 14 wherein the bit sequence in each record in the secondsequential list is arranged in a manner related to frequency ofoccurrence of the corresponding indicator.
 16. The apparatus of claim 15wherein the logic and resources to evaluate a record are adapted suchthat the rank is the number of signs or symptoms in the user definedindicator bitmap which correspond to a “present” value bit in the bitsequence.
 17. The apparatus of claim 16 wherein the logic and resourcesare adapted to report hazardous materials on the output device in anorder of the rank of its corresponding record.
 18. A computerized methodfor use in identifying a hazardous material on a computer having anoutput device, an input device and a computer memory comprising thesteps of: a. storing a first sequential list comprising a multiplicityof fixed length records in the computer memory, wherein each fixedlength record has a relative position in the first sequential list andrepresents a hazardous material, and each fixed length record consistsof a bit sequence wherein each bit can be assigned either a “present”value or an “absent” value wherein each bit represents a member of thegroup consisting of normalized descriptors of an observable property ofa hazardous material, special modifiers, and unassigned positions; b.storing a computer representation in the computer memory, of responseinformation relevant to use with the hazardous materials represented inthe first sequential list; c. displaying a plurality of property listson the computer output device of the type from which a user can makeselections, wherein each property list pertains to an observableproperty, and lists choices which are either normalized descriptor ofthe observable property or special modifiers pertaining to theobservable property; d. accepting at least one selection from a userfrom the computer input device from at least one of the plurality ofproperty lists the at least one selection being either a normalizeddescriptor or a special modifier wherein the at least one selection maycomprise a plurality of different selections; e. storing in the computermemory a user defined selection from each property list from which atleast one selection was made wherein each user defined selectioncomprises a user defined descriptor bitmap which comprises a bitmap ofnormalized descriptors selected, if any, and a user defined modifierbitmap which comprises a bit map of special modifiers selected, if any;f. evaluating a record in the first sequential list of fixed lengthrecords to determine whether a hazardous material represented by therecord is a possible matching hazardous material based on at least onebit wise comparison of each user defined selection with the record; g.reporting the hazardous material on the output device if it is apossible matching hazardous material; h. finding response informationfor a possible matching hazardous material using the relative positionof the record if requested by the user; and i. reporting the responseinformation for the possible hazardous material on the output device.19. The method of claim 18, wherein the step of displaying a pluralityof property lists further comprises displaying each of the plurality ofproperty lists in the form of pop up menus.
 20. The method of claim 18,wherein the plurality of property lists comprise three property lists.21. The method of claim 20, wherein the observable propertiescorresponding to the three property lists comprise color, texture, andodor.
 22. The method of claim 18, wherein each fixed length record inthe first sequential list, comprises a plurality of descriptor groupsand wherein each property list corresponds to a descriptor list and eachchoice on a property list corresponds to one bit in the descriptor list.23. The method of claim 22, where in storing a first sequential listfurther comprises the following acts: a. contextually parsing plainlanguage descriptions of a multiplicity of hazardous materials toidentify a plurality of relevant descriptors and a plurality ofmodifiers pertaining to observable properties of the multiplicity ofhazardous materials; b. normalizing the plurality of descriptors andplurality of special modifiers into a common lexicon of normalizeddescriptors and special modifiers; c. classifying each normalizeddescriptor and each special modifier into one of a plurality ofdescriptor groups, wherein at least one of the descriptor groupscomprises a plurality of special modifiers; d. assigning a binary powerof 2 to each normalized descriptor and to each special modifier in eachdescriptor group, whereby each normalized descriptor and each specialmodifier in each descriptor group is represented by exactly one bit; e.assigning an order to each of the plurality of descriptor groups, suchthat each fixed length record consists of a sequence of descriptorgroups in the order; and f. assigning values to each descriptor group ineach fixed length record that represents a hazardous material, such thatthe sequence of descriptor groups describes the hazardous material. 24.The method of claim 23, wherein a fixed length record represents apossible matching hazardous material, if for each descriptor group inthe fixed length record that corresponds to a property list from whichat least one selection was made, there is at least one bit with“present” value that corresponds to a selected bit, if any, in the userdefined descriptor bitmap, and that there is at least one bit with the“present” value that corresponds to a selected bit, if any, in the userdefined modifier bitmap.
 25. The method of claim 23, wherein a fixedlength record represents a possible matching hazardous material, if foreach descriptor group in the fixed length record that corresponds to aproperty list from which at least one selection was made, each selectedbit in the user defined descriptor bitmap, if any, corresponds to a“present” value bit in the descriptor group, and each selected bit inthe user defined modifier bitmap, if any, corresponds to a “present”value bit in the descriptor group.
 26. The method of claim 18, furthercomprising the steps of: a. loading a second sequential list of fixedlength records into the computer memory, wherein each fixed lengthrecord corresponds to a hazardous material and has a relative positionin the second sequential list and wherein each fixed length record is abit sequence in which each bit in the bit sequence represents either anormalized sign or symptom of an exposure to a hazardous material andwherein every bit has either a “present” value or an “absent” value; b.displaying signs and symptoms on an output device in the form of atleast one list from which a user can make selections, wherein each signand each symptom corresponds to a bit in the bit sequence; c. acceptingat least one selection from the user from the input device of a sign orsymptom wherein the at least one selection may comprise a plurality ofdifferent selections; d. storing in computer memory a user defined signsymptom bitmap corresponding to the at least one sign symptom selection;and e. evaluating a record in the second sequential list of fixed lengthrecords by calculating a rank based on a bit wise comparison between theuser defined sign symptom bitmap and the bit sequence of the record. 27.The method of claim 26, wherein the bit sequence in each record in thesecond sequential list is arranged in a manner related to frequency ofoccurrence of the corresponding sign or symptom.
 28. The method of claim27, wherein calculating a rank comprises computing the number of bits inthe user defined sign symptom bitmap which correspond to a “present”value bit in the bit sequence of the record.
 29. The method of claim 28,further comprising reporting hazardous materials on the output device inan order of the rank of its corresponding record.
 30. Instructions incomputer usable form which carry out the method of claim
 18. 31.Instructions in computer usable form which carry out the method of claim26.
 32. The instructions of claim 30 wherein the computer usable form iscomputer readable form.
 33. The instructions of claim 31 wherein thecomputer usable form is computer readable form.
 34. A method ofpreparing a database of hazardous material properties for use in acomputerized identification of a hazardous material comprising the actsof: a. contextually parsing plain language descriptions of amultiplicity of hazardous materials to identify a plurality of relevantdescriptors and a plurality of modifiers pertaining to observableproperties of the multiplicity of hazardous materials; b. normalizingthe plurality of descriptors and plurality of special modifiers into acommon lexicon of normalized descriptors and special modifiers byreplacing synonymous words and phrases with common wording; and c.classifying each normalized descriptor and each special modifier intoone of a plurality of descriptor groups, wherein at least one of thedescriptor groups comprises a plurality of special modifiers;
 35. Themethod of claim 34 further comprising the acts of: a. assigning a binarypower of 2 to each normalized descriptor and to each special modifier ineach descriptor group, whereby each normalized descriptor and eachspecial modifier in each descriptor group is represented by exactly onebit; b. assigning an order to the plurality of descriptor groups, suchthat the plurality of descriptor groups arranged in the order form afixed length record; and c. assigning values to each descriptor group ineach fixed length record that represents a hazardous material, such thatthe sequence of descriptor groups describes the hazardous material.